Protecting system for photoelectric cells in liquid fuel burner controls



Aprl 15, 1952 BABICZ PROTECTING SYSTEM FOR PHOTOELECTRIC CELLS IN LIQUIDFUEL BURNER CONTROLS Filed Jan. 20, 1948 m m m Patented Apr. 15, 1952UNITED STATES PATENT OFFICE PROTECTING SYSTEM FOR PHOTOELEC- 'TRIC'CELLS [N'LIQUIDFUEL BURNER CONTROLS 'George Babicz, Chicago, Ill.

:Application January 20, 1948,;Ser'al.No.*3,246

`smoke is generated or 'there is an absence of ame or obscurationthereof by the excessive amount of smoke. This isgenerally accomplishedby directing a photo-electric cell upon the chamber in whichthe-Consumption of oil takes place in order to detect any undesirabledegree of smoke generated in the chamber or theabsence of fiame or theobscuration of thelatter by an excessive amount of smoke. The smoke inthe chamber acting upon a photo-electric cell induces-the latter to actupon suitable mechanism for -shutting off the supply of oil andthe motorwhichoperates the oil dispersing mechanism, and as a result of thisaction the 'oil combustion in the chamber is stopped 'so as topermitproper adjustment in .the mechanism supplying "the oil or in themechanism dispersing or firing the -`same in order to eliminatethegeneration of smoke or torecondition the mechanism for firing of the'oil and to effect proper combustion of oil.

The beam of photo-electric cell is usuallydrected'into 'and upon thefire chamber througha tube within which a glass slide is positioned in atransverse relation with the tube and intermediately between thephoto-electrc cell and thefire chamber. Since the tube is incommunication with the chamber smoke and soot often settle upon theglass slide obscuring the beam of .the photo-electric cell, therebyrequiring periodic cleaning of the slide.

To 'prevent settling of smoke `and soot upon the glass slide an airpipe'was connected with the tube aforesaid in order to constantly flowfrom -the tube into the fire chamber for preventing entrance of thesmoke into -the tube. However, the air flowing from the tube oftentimesgenerated ebbor back-'flow permitting a degree of smoke andsoot to enterthe tube and to settle upon theglass slide. This objection was dueprincipally to a single air pipe connecting with the tube-aforesaid, andthe air forced into the tube by a ;single .pipe had :a tendency offlowing within the tube along apertion of the periphery of the latter,:permitting the ebb `or back-flow of the combustion gases from the firechamber into the ;tube aforesaid, and along the periphery of the latteralong which the `air did not suicently :act to ;prevent the ebb orback-flow.

Therefore, the princpal object ,ofthe present invention is the provisionof e'ffic'ent means ;for directing a flow of air in a compactmass 'from;the tube aforesaid into the fire chamber for preventing the ebb orback-fiowof combustionpgases 'into the tube.

Another object of the present inventionisthe provision of simple andelcientmeans .for directing the flow of air into the tube aforesaid fromtwo, substantially ,diametr'cally .opposite l points in the periphery ofthe tube `in .order to force the flow of air in a compact massfromthetube into the fire chamber-.soas to prevent :entrance of r combustiongases `into the tube.

A still further objectof the .presentinvention is the provsion ofatleasta pair of air conduits connected with the air tube aforesaid,through which-air may be ed under pressure into said air tube andexpelled `therefrom into .the fire chamber, so as to engender asymmetrical velocity profle of air in-kthe said air tube ..forpreventingthe combustion gases to enter saidlair .tube and for eliminatingsettling of soot upon the said photo-electric cell .or upon the saidglass slide.

With the above ,general objects in View .and others that willappearasthe invention'isbetter understoocl, 'the same consists .in .the novelseconstructon, combination and arrangement (of parits hereinaftermorefully described,.illustra`ted in..the accompanying drawing and pointedout in theappendd claims. e

In :the drawing forming a part of this application, and .in which likedesignating characters refer to corresponding parts throughouttheseveral VIEWS:

Fig. 1 is a diagrammatic iew, partly insection and partlyinelevation,illustrating relative position of an oil dispersing and burning unit,avalve in theconduit supplying the oil thereto, which Valve iselectronically controlled by a, photo-electric cell, a boileroraosimilarhousing defininga fire chambersin which the oil burns, a.photo-electric cell directed into the fire .chamber through a tube, apair of air pipes connected with said .tube and in front of a glassslidein-the saidtube, nd

-an oil -firing mechanism also eleotronically controlled by thephoto-electric cell;

Fig. 2 is 'a longitudinal cross-sectional ;View through thephoto-electric cell casing and .the tube; and

Fig. 3 -is a transverse:cross-sectional view on lineB-B of Eig. 2.

Referring in detail to the present drawing there erating with saidboiler is an oil dispersing'and burning unit, which includes nozzle l,the outer free end of which is set within wall ID in a transverserelation therewith. i said nozzle H is integrally formed with casing !2.Housing !3 is affixed to the opposite wall of said casing !2, andencloses electric motor [4, which drives shaft l5, passing through andsupported by the rear wall of said casing !2. Connecting with shaft !5is hub IG which supports fan IT. Affixed to the front wall of casing [2,inwardly thereof and adjacent the inner end of nozzle I l is spider !8.The latter is provided with a plurality of openings 19 for permittingpassage of air from casing l2 into nozzle ll. said spider l8 furthercarries an integrally formed tubular hearing 20 for supporting one endof hub 16.

Connecting with the rear wall of said casing !2 is air supply pipe 21,through which air is supplied into said casing !2.

Oil pipe 22 is passed through the rear Vertical wall of housing l3,through motor M, shaft |5 and hub !6, and is in a concentric relationwith nozzle l I, the front end of said pipe 22 terminating a shortdistance rearwardly of the free open end of said nozzle l l. Whenelectronically controlled solenoid valve 34, cooperating with said oilpipe 22 is opened, the oil is permitted to flow out of said pipe 22through its end within nozzle il. There it is dispersed by the airforced into nozzle ll from the casing [2, and through openings [9, bythe action of fan IT. The dispersed oil, indicated by 23, is ignitedelectrically by pilot burner 36' and is caused to burn within the firechamber of the boiler defined by said wall lu.

The valve 34 for opening or shutting o oil pipe 22 is actuatedautomatically and electrcm'cally by well known thermostatic device, notshown in detail, which is controlled through electric wires 35connecting with wires 40, the latter connecting with and leading fromphoto-electric cell 24.

Gas pilot burner 36' includes pipe 36. The latter is passed throughboiler wall n in downwardly inclined direction. said pipe 36 Suppliesthe gas,

which, when ignited, constitutes a pilot which is directed from aboveupon stream 23 of the dispersed oil. The escaping gas is electricallyignited by means of a spark engendered through electrode wi'e 31,concentrically positioned within pipe 36. Wire 31' connects with pipe36. The inner end of said pipe 36 has a constricted mouth with the endof electrode 31 in a spaced relation therewith. Pipe 36 itselfconstitutes ground, so that when electric current is passed throughelectrode wire 37 and Wire 31' electric spark is engendered at the innerend of pipe 35 for igniting the escaping gas through the inner open endof pipe 36.

The supply of gas through pipe 36 is controlled by valve 38 actuatedeither by a mercury or electronically controlled switch, with whichwires 39 connect. The opposite ends of said wires 39 are connected withphoto-electric cell 24 through wires 43.

In the event the dispersed oil does not properly burn and generates anundesirable degree of smoke, or in the event the flame has becomeextinguished for some reason, photo-electric cell 24 directed againstthe fire chamber, becomes in either event responsive for the purpose ofautomatically shutting off valve 34 which is connected with oil pipe 22and of automatically shutting ofl" valve 38.

Thus when photo-electric cell 24 becomes desensitized due to theobfuscation by smoke or lack of flame in combustion chamber [0, and theconsequent de-energization of electric circuits through wires 40, andwires 35 and 39, respectively, for actuating valves 34 and 38,respectively, the supply of oil through pipe 22 and the supply of gasthrough pipe 36 will be stopped. By this means the supply of oil and itsdispersal and igniting in chamber lfl will be efiectively arrested,thereby rendering the entire apparatus inoperative.

said photo-electric cell 24 is positioned within casing 25, which issupported by tube 26. The opposite end of said tube 26 is aixed to wall!0, and communicates with opening 21 made in said wall 10. said casing25 likewise is in communication with said tube 26. Both said tube 26 andopenin 21, the latter being a continuation of the adjacent end of saidtube 26, are at an incline, being directed upon the fire chamber in theboiler for permitting the view of said chamber by said photo-electriccell.

Integrally formed with said tube 26, and adjacent its end which isnearest to casing 25, is a rectangular frame 28, which at one of itsedges is provided with a slot through which glass slide 29 may beinserted into or withdrawn from said frame 28 and in a transverserelation with tube 26, as is clearly seen in Figs. 2 and 3. Said slide29 is provided with ear 30 which may be manually grasped for shiftingsaid slide 29. The purpose of said slide 29 is to keep away the heat andcombustion gases from casing 25 so that photoelectric cell 24 may notbecome overheated and in order that the same may be maintainedunobscured by smoke and scot which otherwise might enter thereintothrough said tube 26 and opening 21. However, smoke entering tube 26would eventually cause the settling of soot upon slide 29, requiringperiodic removal thereof from frame 28, for periodic wiping oil of sootwhich has settled thereon. Unless this was done photo-electric cell 24would become responsive to the obscuring film upon slide 29 and withoutregard to any undue degree of smoke or the absence of flame in the firechamber, thereby rendering said photoelectric cell 23 inefficient in itsoperation.

In order to obviate and completely prevent entrance of any combustiongases, and consequently any solid combustion particles, into tube 26,and thereby to completely prevent settling of scot upon slide 23, thepresent invention was designed. The same includes manifold 3! connectedwith the rim wall of casing !2, adjacent the front end thereof. saidmanifold 3! carries T-joint 32, with the horizontal portion of which apair of air pipes 33 connects. The opposite ends of said pipes" 33 areconnected with tube 25, intermediately of slide 29 and wall o, in theproximity of said slide 29, and at two diametrically opposite points onthe periphery of said tube 26.

Tube 26 may be corrugated as shown for the purpose of causing heatradiation for maintaining tube 26 comparatively cool.

Part of the air stream driven by fan I'l is forced into manifold 3! fromwhere it is distributed into pipes 33 and forced into tube 2'6 at twoopposite points of the periphery of the latter. The air thus forcedthrough said pipes 33 brings about a symmetrical velocity profile intube 26 and opening 21 and the air is expelled through said opening 21into the boiler or the fire chamber of any oil consuming apparatus. Dueto the symmetrical velocity profile of the air engendered in tube 26 theback-flow either of air or of combustion gases from -the fire chamberinto tube 26 in the direction of slide 29 is effectively eliminated andprevented. In' the devices wherein' only 'oneair pipe, such as pipe33,-i`s used, the backflower 'the air or of the combustion gasesinto thetube and toward slide 29 is not prevented,` 'due'to' the `fact that airforced through a single tube has a tendency to travel along the tubeadjacent -a, portion of its periphery, thereby permitting 'the'back-flow lengthwise of the tube along the-'remaining portion of theperiphery thereof. By providing *at least two air pipes, the outlets of-w-hich are preferably at diametrically opposed points'o'f theperipheryof the tube, the objections noted are effectively eliminated, with theresult that there is practically no settling of the soot upon thesurface of :slide 29 which is exposed within tube :26, therebyeliminating frequent periodic withdrawals of slide 23 for cleaning thesame.

Since switches for'controlling valves 34 and 38, the ther'mostat, andthe mech'anism for'thermostatically controlling the va'lves, are well:known in the art, the same are-not'shnwn in the drawing. The inventionresides entirely in the piurality "of air pipes 33 'connecting with tube28 for the purpose of forcing'the air into said tube 26 and efiecting asymmetrical velocity profile of the air in tube 26 for the purposesindicated.

The device herein disclosed does not presuppose the use of glass slide29 under all conditions. 'It may well be that the symmetrical velocityprofile of air engendered in tube 26 may reduce the heat in said tube 26to such a degree as to make it possible to dispense with slide plate 29entirely, bearing of course in mind that the primary purpose and objectof slide 29 was to protect photo-electric cell 24 from the heatengendered in tube 26. Then again, there may be means other than slideplate 29 for protecting photo-electric cell from heat. If slide plate 29is dispensed with, it still will be necessary, and more so, to protectthe photoelectric cell from the settling of scot thereon. What applicantdesires to convey is the fact that slide piate 29 is not anindispensible element in his invention. The latter will work whether forthe protection of slide plate 29 or for the protection of photo-electriccell 24 directly when the slide plate has been removed from theassembly.

While there is described herein a preferred embodiment of the presentinvention, it-is nevertheless to be understood that minor changes may bemade therein without departing from the spirit and scope of theinvention as claimed.

What I claim as new is:

1. In a liquid fuel burning apparatus, a housing defining a firechamber, said apparatus including means for supplying, dispersing andigniting the iuel for causing the same to be consumed in said firechamber, a tube supported outwardly of said fire chamber and openingthereon, a photo-electric cell mounted at the outer end of said tube,said photo-electric cell being directed upon said fire chamber, saidtube being provided with a transparent slide in a transverse 'elationtherewith intermediately of said fire chamber and said photo-electriccell, said photoelectric cell being adapted to respond to combustionfailure to render said means inoperative, and means for engendering asymmetrical velocity profile of air in said tube intermediately of saidslide and said fire chamber and expelling the air into said firechamber, said last named means including at least a pair of air conduitsconnected with said tube for injecting therethrough air under pressure.

2. In a liquid fuel burning apparatus, a housing defining a firechamber, said apparatus including G means for supplying, dispersing andignitingthe fuel for causing the sa'me to be: consumed in said 'firechambena tub'e supported outwardly of 'said fire chamber andopeningthere'on, a photo-'le'ctric cell mounted-at the 'outer :end of saiditube, said photo-electric-cell being directed -uponsaid fire chamber,said tube 'being provided with a transparent slidein a transverserelation therewith intermediatly-ofsaid fire chamber and said'photo-electric cell, said photo-'electric cell being adapted to respondto combustion `failure to render said means inoperati'v'e, and 'meansfor in- 'j'ecting under'pressure into said -tub'e intermediateiy 'ofsaid slide 'and said fire chambe'r'str'eams of air from a plurality 'ofpoints 'on'the p'eriph'ery of said tube in a 'substantially uniformly:spaced 'relation on a transverse plane of said tube.

3. In 'a liquid fuel burning apparatus, *a housing 'denin'g a firechamber, said apparatus including means for supplying, dispersing andig-niting 'the 'fuel'for causing the .same to 'b'e -consumed in saidfire chamber, a tube supported outwardly of said 'fire chamber andopening thereon, a `photo-"electriccell -mounted at 'the outer end` ofsaid 'tube, said photo-'electriccell being directed upon said firechamber, said tube being provided with a transparent slide in atransverse relation therewith intermediately of said fire chamber andsaid photo-electric cell, said photo-electric cell being adapted torespond to combustion`fai1ure to render said means inoperative, andmeans for injecting under pressure into said tube intermediately of saidslide and said fire chamber streams of air from a plurality of points onthe periphery of said tube, said last named means including a pluralityof air conduits connecting with said tube in a substantially uniformlyspaced relation on a transverse plane of said tube.

4. In a liquid fuel burning apparatus, a housing definin a fire chamber,said apparatus including means for supplying, dispersing and ignitingthe fuel for causing the same to be consumed in said fire chamber, saidmeans including an air compressing chamber, a tube supported outwardlyof said fire chamber and opening thereon, a photo-electric cell mountedat the outer end of said tube, said photo-electric cell being directedupon said fire chamber, said tube being provided with a transparentslide in a transverse relation therewith intermediately of said firechamber and said photo-electric cell, said photo-electric cell beingadapted to respond to combustion failure to render said meansinoperative, and means for generating a stream of air of uniform densityin said tube intermediately of said slide and said fire chamber andexpelling the same into said fire chamber for preventing a back-flow ofcombustion gases from said fire chamber into said tube, said last namedmeans including a plurality of air conduits connectin with said tube atpoints in a substantially uniformly spaced relation on a transverseplane of said tube, the opposite ends of said air conduits beingconnected with said air compressing chamber for forcing the air fromsaid air compressing chamber into said tube through said air conduits.

5. In a liquid fuel burning apparatus, a housing defining a re chamber,said apparatus including means for supplying, dispersing and ignitingthe fuel for causing the same to be consumed in said fire chamber, saidmeans including an air compressing chamber, a tube supported outwardlyof said fire chamber and opening thereon, a photo-electric cell mountedat the outer end of said tube, said photo-electric cell being directed.

upon said fire chamber, said tube being provided with a. transparentslide in a transverse relation therewith intermediateiy of said firechamber and said photo-electric cell, said photo-electric celi beingadapted to respond to combustion failure to render said meansinoperative, and means for generating a stream of air of uniform densityin said tube intermediately of said slide and said fire cha-mber andexpelling the same into said fire chamber for preventing a back-flow ofcombustion gases from said fire chamber into said tube, said last namedmeans including a pair of air conduits connecting with said tube atdiametricaily opposed points of the periphery thereof, the opposite endsof said air conduits being connected with said air compressing chamberfor foreing the air from said air compressing chamber into said tubethrough said air conduits.

6. In a liquid fuel burning apparatus, a housing defining a firechamber, said apparatus ini said tube. said photo-electric ce beingdirected upon said fire chamber, said photo-eiectric cell being adaptedto respond to combustion failure to render said means inoperatve, andmeans for engendering a, symmetricai velocity profile of air in saidtube intermediately of said photo-electrc cell and said fire chamber andexpelling the air into said fire chamber, said last named meansincluding at least a. pair of air conduits connected with said tube forinjecting therethrough air under pressure.

GEORGE BABICZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,745,178 McCabe Jan. 28, 1930FOREIGN PATENTS Number Country Date 4911714 Great Britain Sept. 1, 1938

